Abstract: The 4.0 Mt/a VGO hydrocracking unit of Zhejiang Petrochemical Company adopted UOP’s UnicrackingTM hydrocracking technology with the graded catalysts of the hydrotreating catalysts HYT-6219 and hydrocracking catalyst HC-185LT. Since the start-up, the unit has been running stably at over 95% of the load. Based on the research and summary of the unit operation optimization, the average amount of 57 t/h of RFCC diesel and coker diesel was blended as feed, and all the products were qualified, the yield of （heavy naphtha + jet fuel + diesel）was increased by 5.17 percentage points．The No. 5 industrial white oil (I) with kinematic viscosity of 4.345 mm²/s and flash point (open cup) of 126℃ was produced from the diesel side line of fractionator．The yield of jet fuel was increased from 20.7% to 26.6%, and the production was increased by 35.5 t/h compared with the design．The F0 pentane foaming agent with isopentane content of 99.20%andtotal pentane content of 99.66% was produced on deisopentanizer．Through a series of optimized operation, the value added product and the output of the unit were improved, and the overall operation economy of the unit was significantly increased．The advantages of flexible product structure adjustment of VGO hydrocracking unit in refining and chemical integration project were achieved．

Key words: Hydrocracking, RFCC diesel, coker diesel, Industrial white oil, Jet fuel, pentane foaming agent